One way to do this is to open up the computer but what if you do not what to take the time to shut down the computer, pull it apart, identify the parts, and then put it all back together.

A better way can be done with Windows. Windows allows you to view the processor speed and the ammount of RAM. To do this, click on start, then right click My Computer or Computer in Vista. Now left click properties. A window will show up.

Follow up:

However, this method does not show you what video card that you have or what hard drive you have. To find out more details about a computer's hard ware. Click on Device Manager.

As you can see, the video card in my laptop, is a Nvidia GeForce 9500M GS. Which can be found by expanding the Display adapters.